Keywords: polypyrrole, polyaniline, hybrid materials, composites, cellulose substrates, paper fibres, paper sheets, wood, merino wool fibres, kaolinite particles, conducting polymers, natural fibres, silver nanoparticles, anti-microbial, nanotechnology, hydrogen bonding
Hybrid materials of conducting polymers with natural fibres and silicates
The preparation, characterisation and properties of new hybrid materials of the conducting polymers polypyrrole and polyaniline with cellulose substrates in the form of paper fibres, paper sheets and wood; merino wool fibres; and kaolinite particles are presented. The conducting polymers form as spheres of about 50-150 nm that are fused together as a continuous coating which fully encapsulates the substrate fibre or particulate surface. The polymer is chemically bound to the hydroxyl or amine groups on the substrate surface by hydrogen bonding. The resulting hybrid materials exhibit the properties of both precursors. Thus the electrical conductivity, optical and chemical properties of the particular conducting polymer are combined with the mechanical strength and integrity of the wood and cement board, the tensile strength and flexibility of the wool and paper fibres and paper sheets, and particulate nature of the silicates respectively. The redox properties of the conducting polymer can be used to deposit silver nanoparticles on the hybrid surface thereby imparting anti-microbial activity to it. These new hybrid materials provide an attractive approach to overcoming the inherent processability difficulties encountered with conducting polymers and open up opportunities for the development of new consumer products and applications.